This disclosure relates generally to the release of a substance into a body of water. Specifically, the disclosure relates to operations for managing substance releases, which utilize a thickness detection apparatus.
This section is intended to introduce various aspects of the art, which may be associated with one or more embodiments of the present disclosure. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of prior art.
In the oil and gas industry, hydrocarbon substances are accessed via a wellbore to provide a fluid flow path to a processing facility. Some of these hydrocarbon resources are located under bodies of water, such as lakes, seas, bays, rivers and/or oceans, while others are located at onshore locations. To transfer hydrocarbons from such locations, a pipeline and/or one or more different vessels (e.g., ship or tanker trucks) may be utilized through various segments from the wellbore and the processing facility.
Additionally, hydrocarbons may be transferred from a production region to another region for consumption/processing into hydrocarbon-based products or from one hydrocarbon storage location to another. Transfer of hydrocarbons between such locations often requires one or more different vessels and routes over bodies of water, such as lakes, seas, bays, rivers and/or oceans.
Offshore leaks and/or spills may be problematic due to the hydrocarbon substances being released into a body of water. Typically, the hydrocarbons may form a slick on the surface of the water, for example an oil slick. Various response techniques may be utilized to manage the oil slick. For instance, chemicals may be added to the oil slick and mixed with the oil slick to break apart the hydrocarbon substances. In other situations, the oil slick may be ignited to burn off the oil within the slick or mechanical recovery may be utilized to capture the hydrocarbons.
In managing an oil slick, various factors (e.g., spatial distribution and thickness) should be considered as part of the assessment. The spatial distribution and thickness are useful in estimating the volume of hydrocarbons present in the oil slick. For example, conventional practice for marine oil spills is that 90% of the oil is located in 10% of the area as most of the slick is very thin. Determining the oil slick thickness is useful for oil spill response for many of the different response techniques. For example, mechanical recovery and in situ burning are more efficient on a thick oil slick. Also, dispersant dosage requirements change based on the slick thickness.
While the spatial distribution is typically estimated from visual inspection, conventional approaches do not adequately estimate the thickness of the oil slick. For example, conventional approaches typically utilize aircraft to determine the location of an oil slick for marine vessels. With this approach, a trained spotter or an instrument that detects an electromagnetic radiation signal from the slick is located in an airplane and in communication with response vessels. The challenge is that visual and electromagnetic radiation indicators are unable to distinguish oil thicker than about 0.1 mm.
An additional challenge is that for a large spill, each spotter is responsible for multiple response vessels, which requires the spotter in the plane to divide attention between the different response vessels. This approach has proven inefficient because identifying oil slicks from a marine response vessel combined with their dynamic nature at sea requires the spotter plane to focus on a single marine vessel until it is directly adjacent to the oil slick since it is very challenging to identify oil slicks that are more than a few tens of meters away from vessels at sea. Unfortunately, spotter planes are often unable to dedicate attention to a single vessel for the time required to efficiently guide it onto a slick. Accordingly, conventional methods fail to provide simple remote identification and effective estimation of the thickness of marine oil slicks.
WO2013/162790 describes several techniques to measure the thickness of an oil slick using an airborne detection device. The various techniques described measure the thickness of an oil slick at various distinct locations. One technique described includes lowering a camera into the oil slick to determine the thickness at the location.
However, it is desired to further enhance spill response operations by quickly and efficiently determining the areas of highest content of the released substance within a spill. For example, an oil spill may have 90% of the oil located in 10% of the area prior to substantial weathering of the spill. A desire also exists for a detection method that is capable of being stored on a vessel and that can quickly and efficiently identify the thickness of the oil slick. The ability to quickly and efficiently determine the thickest area of the released substance can improve the effectiveness of the response efforts.